The use of air filtration and venting technology, such as incorporated into vehicle fuel systems and the like, is known in the prior art. Examples of these include the fuel vapor recovery system for a vehicle disclosed in U.S. Pat. No. 5,058,693 to Murdock et al., and in which a charcoal canister is connected to the fuel tank for collecting fuel vapors from the tank, such as during refilling. Upon starting the vehicle, the canister is purged if accumulated vapors and receives atmospheric air to fill the purged volume. A filter is remotely connected by a hose to the air inlet of the canister for removing dirt, dust and water from the incoming air.
Lin et al., U.S. Pat. No. 8,052,768, teaches an air filter assembly for removing dust from an intake airflow associated with an internal combustion engine fuel system. A housing includes an air inlet formed in an upper portion and an air outlet. A plurality of vertically extending baffles are disposed in the housing between the upper and lower portions and form vertically extending channels, a first of which receiving the air entering the housing from the air inlet. The air passes laterally outwards in the housing successively to the other vertical channels in a serpentine flow successively upwards and downwardly through horizontally interconnecting channels prior to existing the housing through the air outlet. The bottom of the housing extends across a bottom of each of the plurality of channels for retaining dust within the housing and a filter is disposed in one of the plurality of vertically extending channels in a path of the serpentine airflow.
Nakamura et al., U.S. Pat. No. 7,097,697, teaches a fuel vapor treatment device for a vehicle including a casing having a charge port connected to the fuel tank, a purge port connected to an intake side of an engine, and an atmospheric air port through which atmospheric air is introduced. A fuel vapor adsorbing material is filled in the casing, along with a filter disposed between the atmospheric air port and the adsorbing material to trap dust contained in the atmospheric air. A baffle plate is disposed in the casing and between the atmospheric air port and the filter so that atmospheric air strikes against the baffle plate to change its flow into a generally radial direction to flow through the annular space to the filter.
Finally, Steinman et al., U.S. Pat. No. 7,699,042, teaches a filtration device for use with a fuel recover system having a housing defining a chamber with an upper end and a lower end. A cap is configured to be positioned on and close to the upper end of the housing, the cap defining a helical extending passageway toward the lower end of the chamber and including an air inlet such that air entering the chamber is directed to rotate in the chamber about the rotational axis wherein a centrifugal force of the rotating air filters out contaminants contained therein and a downward force of the air urges the contaminants toward the lower end and through an air outlet for removing the filtered air from the device.